This invention relates to a seal and methods of sealing field emission devices and more particularly, to a high vacuum seal in devices with a flat profile.
Flat panel displays incorporating field emission devices require good vacuum conditions for peak performance and long operating lifetimes. The method used to make the vacuum seal greatly influences the overall vacuum conditions. Because a field emission device (FED) has a larger surface area-to-volume ratio than almost any other vacuum product, the task of producing good vacuum is much more difficult than in other vacuum devices.
Many methods for manufacturing sealed vacuum envelopes, i.e., FED packages, use vitreous frit to seal the anode to the cathode. To achieve high volume manufacturing, FED packages must be moved to a curing chamber or station within a few minutes of being sealed to free up the vacuum chamber. Until the frit cures, however, it remains in a low viscous state, and any relative movement of the components of the envelope can create a misalignment that can fail the package. To avoid this problem, present methods cure sealed vacuum envelopes in the same chamber the seal is made, which impedes high production throughput.
Thus, there is a need for a sealed vacuum envelope and methods of producing the sealed vacuum envelope which greatly increases throughput and which allows the sealed vacuum envelope to be handled while the frit is in a low viscous without the risk of component misalignment.